This power control from a 1968 Motorola manual shows how to use a contemporary diac as a zero-crossing detector. The SCR is of the type depending on the power of the load.
Found in a PE Hobbyst Handbook, this circuit checks if there is voltage in a power outlet by...
Here is a high-quality intercom for demanding readers. The circuit is from a 1982 documentation. Of course,...
This circuit shows how to use a low current read switch to control high power loads. The circuit...